A series of N, N'-disubstituted furazano-and furoxano [3, 4-b] piperazines la4 and 2b-d have been synthesized from N, N'-disubstituted 2, 3-piperazinedione dioximes 5a-d by base- promoted dehydration and by basic potassium ferricyanide oxidation, respectively. The N, N'- disubstituted 2, 3-piperazinedione dioximes were synthesized by reacting the appropriate N, N'-disubstituted ethylenediamine with dichloroglyoxime. Also studied was the reaction of 3 ...